uk.ac.ebi.fg.biostudies.lucene.AnalyzerUtils.java Source code

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Here is the source code for uk.ac.ebi.fg.biostudies.lucene.AnalyzerUtils.java

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/*
 * Copyright 2009-2015 European Molecular Biology Laboratory
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package uk.ac.ebi.fg.biostudies.lucene;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.SimpleAnalyzer;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.analysis.tokenattributes.OffsetAttribute;
import org.apache.lucene.analysis.tokenattributes.PositionIncrementAttribute;
import org.apache.lucene.analysis.tokenattributes.TermAttribute;
import org.apache.lucene.analysis.tokenattributes.TypeAttribute;
import org.apache.lucene.util.AttributeSource;
import org.apache.lucene.util.Version;

import java.io.IOException;
import java.io.StringReader;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

/**
 * Class provided as source for 'Lucene In Action, 2nd Edition'
 */
public class AnalyzerUtils {
    public static void displayTokens(Analyzer analyzer, String text) throws IOException {
        displayTokens(analyzer.tokenStream("contents", new StringReader(text))); //A
    }

    public static void displayTokens(TokenStream stream) throws IOException {

        TermAttribute term = (TermAttribute) stream.addAttribute(TermAttribute.class);
        while (stream.incrementToken()) {
            System.out.print("[" + term.term() + "] "); //B
        }
        System.out.println();
    }

    public static List<String> getAnalyzedTokens(Analyzer analyzer, String text, boolean sortedAlphabetically)
            throws IOException {
        return getAnalyzedTokens(analyzer.tokenStream("contents", new StringReader(text)), sortedAlphabetically);
    }

    public static List<String> getAnalyzedTokens(Analyzer analyzer, String text) throws IOException {
        return getAnalyzedTokens(analyzer.tokenStream("contents", new StringReader(text)), false); //A
    }

    public static List<String> getAnalyzedTokens(TokenStream stream) throws IOException {
        return getAnalyzedTokens(stream, false);
    }

    public static List<String> getAnalyzedTokens(TokenStream stream, boolean sortedAlphabetically)
            throws IOException {

        List<String> result = new ArrayList<String>();
        TermAttribute term = (TermAttribute) stream.addAttribute(TermAttribute.class);
        while (stream.incrementToken()) {
            result.add(term.term());
        }

        if (sortedAlphabetically) {
            Collections.sort(result);
        }

        return result;
    }

    public static String getTerm(AttributeSource source) {
        TermAttribute attr = (TermAttribute) source.addAttribute(TermAttribute.class);
        return attr.term();
    }

    public static String getType(AttributeSource source) {
        TypeAttribute attr = (TypeAttribute) source.addAttribute(TypeAttribute.class);
        return attr.type();
    }

    public static void setTerm(AttributeSource source, String term) {
        TermAttribute attr = (TermAttribute) source.addAttribute(TermAttribute.class);
        attr.setTermBuffer(term);
    }

    public static void setType(AttributeSource source, String type) {
        TypeAttribute attr = (TypeAttribute) source.addAttribute(TypeAttribute.class);
        attr.setType(type);
    }

    public static void displayTokensWithPositions(Analyzer analyzer, String text) throws IOException {

        TokenStream stream = analyzer.tokenStream("contents", new StringReader(text));
        TermAttribute term = (TermAttribute) stream.addAttribute(TermAttribute.class);

        int position = 0;
        while (stream.incrementToken()) {
            System.out.print("[" + term.term() + "] ");
        }
        System.out.println();
    }

    public static void displayTokensWithFullDetails(Analyzer analyzer, String text) throws IOException {

        TokenStream stream = analyzer.tokenStream("contents", // #A
                new StringReader(text));

        TermAttribute term = (TermAttribute) // #B
        stream.addAttribute(TermAttribute.class); // #B
        OffsetAttribute offset = (OffsetAttribute) // #B
        stream.addAttribute(OffsetAttribute.class); // #B
        TypeAttribute type = (TypeAttribute) // #B
        stream.addAttribute(TypeAttribute.class); // #B

        int position = 0;
        while (stream.incrementToken()) { // #C
            System.out.print("[" + // #E
                    term.term() + ":" + // #E
                    offset.startOffset() + "->" + // #E
                    offset.endOffset() + ":" + // #E
                    type.type() + "] "); // #E
        }
        System.out.println();
    }

    public static void setPositionIncrement(AttributeSource source, int posIncr) {
        PositionIncrementAttribute attr = (PositionIncrementAttribute) source
                .addAttribute(PositionIncrementAttribute.class);
        attr.setPositionIncrement(posIncr);
    }

    public static void main(String[] args) throws IOException {
        System.out.println("SimpleAnalyzer");
        displayTokensWithFullDetails(new SimpleAnalyzer(), "The quick brown fox....");

        System.out.println("\n----");
        System.out.println("StandardAnalyzer");
        displayTokensWithFullDetails(new StandardAnalyzer(Version.LUCENE_CURRENT),
                "I'll e-mail you at xyz@example.com");
    }
}